This invention relates to plugs adapted for insertion into the ends of hollow cores used for roll packaging elongated continuous material, and more particlarly to plugs useful in facilitating handling of tubular cores and in preventing physical damage to the ends of said cores.
A number of commercial products fabricated in elongated continuous form are generally packaged for storage, shipment and use in the form of a rolled winding on a cylindrical core. Elongated products commonly packaged in this manner include sheet or web structures such as paper, carpeting, plastic film and foam, knitted goods, woven cloth, laminated structures, and the like, and strand products such as cables, ropes, wires, cords, yarns, hoses, tubes, and the like.
The core is generally hollow or tubular in order to minimize the total weight of the package and is generally fabricated of inexpensive material such as paper to obviate the need for storage and/or return of the empty core. In the course of the usual industrial handling, the ends of the core, which in some package types protrude beyond the winding of material on the core, are exposed to conditions which may cause physical deformation, as by crushing or striking forces, or contact with water. Malformed ends of the cores can cause damage to the wound material, or may impair the ability of the wound material to properly unwind, or may prevent the proper mounting of the core on equipment to provide axial rotation for unwinding.
Specially designed fittings have been disclosed in the prior art for use in protecting the ends of tubes used for the packaging of wound continuous elongated products. One such fitting is the subject of U.S. Pat. No. 1,989,053 to Hills, et al, which relates to a protective device consisting of a flange attached to a plug, and a wrapping for the wound material, attached to the flange. Although the fitting of Hills, et al may afford a measure of protection for the ends of the tubes during shipment, the fittings must be removed during operations requiring the unwinding or use of the wound material. The Hills, et al fittings are also not compatible with present day methods for the lifting and moving of heavy tube packages. Such methods utilize lift trucks or other suitable equipment having clamping means which grip the ends of the tube by means of dowels which enter holes axially located in a flange or end plate of the tube.
The fittings of Hill, et al and other references are fabricated of corrugated paperboard because of the inherent stiffness, light weight, and low cost of this material. Because of the nature of many large scale manufacturing operations, it is generally expedient to utilize multiple layers of corrugated paperboard in a manner such that the direction of the corrugations or flutes is essentially the same in each layer.
It is an object of the present invention to provide protecting means for the ends of tubes used for the packaging of wound continuous elongated products wherein said protecting means facilitates the handling of said tubes by lift trucks and permits the mounting of said tubes on means for the unwinding of said wound products. It is another object to provide a protecting means for the ends of tubes used for forming packages of wound continuous elongated products wherein said packages containing said protecting means can be stacked on end and can be mounted on means for the unwinding of said wound products. Other objects and advantages will become apparent hereinafter.